Gordon Brown used what may be his last European summit to explore the idea of establishing a new European "peace corps" of thousands of volunteers performing charity and aid work across the developing world.

Under the Lisbon treaty, which came into force in December, Lady Ashton, the Labour peer and former leader of the House of Lords, is the recently appointed head of European foreign policy at the helm of a new European diplomatic service involving up to 8,000 staff at 137 embassies across the world.

Lady Ashton unveiled her blueprint for the creation of the new diplomatic service.

On the fringes of an EU summit in Brussels, the prime minister spoke to Ashton about the new peace corps, British diplomats said, and also raised the issue with José Manuel Barroso, the president of the European commission.

The Lisbon treaty talks vaguely about establishing a new European volunteer service, which would probably be modelled on the US peace corps, and include a significant number of British volunteers.

"A European peace corps would inject fresh energy into our own ambitions for the EU to play a practical role in meeting the global challenges of stability and poverty," said the prime minister.

Brown's move follows a Foreign Office analysis of the potential for innovation thrown up by the new European service, which has been fought over for weeks in Brussels, pitting the European commission against the bigger governments in the EU and also angering the small countries who fear their involvement could be sidelined.

Ashton presented her ideas on the shape and powers of the service yesterday, but arguments are still raging over divvying up the plum posts, how appointments will be made, the languages that will be used, budgets and staffing.

The European parliament rejected Ashton's proposals, signalling further battles in the weeks ahead.

British government sources said that because of the various problems implementing the Lisbon treaty, nothing had yet been done about the new peace corps concept.

Diplomats spoke of a "cadre of several thousand, not dissimilar to the US peace corps, working in Africa and Asia".

Volunteers could take part for periods of between six months and two years and the projects would be administered, supported, and managed by the new diplomatic service, known as the European external action service.

The European commission is expected to table further proposals later this year, with diplomats saying the scheme could be up and running by 2012.

"It would be the human face of the European Union overseas. It could be a serious effort at improving the EU's impact," said a British diplomat.